I suppose most paramedic students experience some sort of frustration when they are going through Cardiology and trying to integrate what they are learning to recognize on the strip into the ACLS algorhythm and at the same time figure out how to implement their newly found knowledge into ever increasing treatments and interventions they have only read about thus far.
I struggled a little with the concept of recognizing when a dysrhythmia is a good thing that needs to be coddled and supported and when it needs to be escorted from the building in an expeditious fashion so to speak.
The concept became clear for me with a political metaphor of all things.
Before we get the political unrest – Let’s look at a much simplified explanation of how the “government” of the heart is supposed to work…
In normal conduction the electrical activity of the heart is “governed” by the intrinsic rate of the Sinoatrial node (SA) – due to differences in the slope of diastolic depolarization the specialized myocytes of the SA node reach their action potential stage faster then the other specialized conduction cells. Each of these specialized cells has an intrinsic rate that is governed by a leak of ions through the cell membrane leading them towards to their action potential, and they all want to be the “guy in charge” but the “influence” of the SA node is so powerful that they never get the chance to act out due to the SA nodes impulse reaching them before they can act out on their own.
When things start to go awry and the protestors march or occupy or whatever type of political unrest makes it easier for you to comprehend things can change a little.
Let’s start with default rhythms and how I think about them – If the SA node is “in charge” of this political process let’s call it the president – the president of the heart belongs to the sinus party and when he is running the show – we see a sinus rhythm on the strip.
What happens when the “president” for whatever reason can’t do its job – Much like the democratic process we have here in the USA the heart has a backup plan in place – a “Vice President” if you will – the AV node the AV node tends to look like he belongs to the sinus party as well, but subtle difference tell us he really belongs to the junctional party – which shows up as a junctional rhythm on the 12 lead. It runs a little slower then the president does, but can be quite effective at running things.
So what if the President and the Vice president are incapacitated – in our form of Government the Speaker of House would be next in line – in the heart it would be the ventricles – The ventricles belong to a totally different party then either the president or the vice president and they don’t try to hide it either – they appear as a ventricular rhythm on the 12 lead looking very different (in most cases) then either the sinus or junction. The ventricles are slower still and (for default purposes we’ll say they) run things marginally usually just enough to get by.
The heart and our Government are set up to allow lower level sites to take over or pick up the slack for a failed or ineffective “leader” when this happens it’s a default rhythm and we should do everything we can to nurture and support it – drastic interventions into this type of rhythm can lead to “anarchy” completely knocking out the system of government and leading to chaos.
On the other hand – we have usurping rhythms…
These rhythms are the “little Latin generals” staging a coup. For whatever reason an ectopic site (little Latin general) goes off the reservation and decides it can do better job running things and tries to take over. If the “little general” manages to fire faster then “el presidente” he can totally usurp the normal leader’s authority and due to those same conduction fibers make the higher ups bend to his will. Little Latin Generals usually work really fast as evidenced by their tachycardic rate.
Generally speaking the heart (and the Government) is in total chaos at this point and maybe minimal stuff gets done – but all of the Government is in total disarray and the “citizens” (tissues in need of perfusion”) suffer –
These are the instances when as a medic we need to call in “the Marines” and provide some sort of intervention to restore order and the normal balance – whether that means a surgical strike with a specific medication to try and interrupt the ectopic sites overactive ambition or a carpet bombing with the defibrillator where we force em to “ride the lightening” and hopefully reset the normal balance depends on both the rhythm strip and the patients general presentation.
The metaphor and concept seems to work for me and makes it easy to remember – Does it make sense to you? What kind of ways do you use to understand complex processes and how they relate to your treatment plan?